Pattern sewing device for sewing machines



Dec. 5, 1967. L. BONO 3,356,052

PATTERN SEWING DEVICE FOR SEWING MACHINES Filed March 15, 1965 2 Sheets-Sheet 1 10 9 14-15 6 1 i u W 2 H 11 I 8" J FIG. 1

, INVENTOR wxqr non ATTORNEYS Dec. 1967 BONO 2 3,356,052

PATTERN SEWING DEVICE FOR SEWING MACHINES Filed March 15, 1965 2 Sheets-Sheet 2 f I 5 17 16 v I. 35 20 17 16 .w' I f V30 I/M; 26 I) 8 24 5g 2 21 a 13 22 23 i 20 I 26 22 21 27 28 26 13 o 29 12 FIG.2 F|G.3

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INVENTORV ATTORNEYS United States Patent PATTERN SEWING DEVICE FOR SEWIYG MACHINES Luigi Bone, Pavia, Italy, assignor to Necchi Societa per Azioni, Pavia, Italy Filed Mar. 15, 1%5, Ser. No. 439,869

Claims priority, application Italy, Mar. 20, 1964,

5,893/ 64, Patent 717,653 Claims. (Cl. 112-158) ABSTRACT OF THE DISCLOSURE A sewing machine for sewing an ornamental pattern in accordance with either of various pattern-defining cams and wherein a change in sewing pattern is effected through a single maneuver of the machine operator whereby disengagement of one of said cams automatically effects engagement of another of said cams relative to the oscillatory needle bar frame.

The present invention relates to sewing machines in which the needle bar is made to oscillate transversely of the direction in which the fabric moves in order to sew a pattern, usually an ornamental pattern, rather than along a straight line.

In known machines of this type, the needle bar supporting frame is movably supported from the machine housing and is made to oscillate by means of a reciprocating rod whose reciprocal movements conform to the profile of either one of different pattern cams which form part of an ornamental pattern sewing device. The oscillatory pattern defined by the needle bar frame can be changed by simply changing from one cam to another. This changing heretofore has required two separate maneuvers on the part of the machine operator: first, the operator had to shift the cam then in use out of its driving relationship with the reciprocating rod; and second, the operator had to shift another cam into said driving relationship.

An object of the present invention is to provide an ornamental pattern sewing device which comprises a stack of pattern cams and wherein the changing of cams is realized through a single maneuver by the machine operator.

A further object is to provide such a device wherein the disengagement of one cam automatically causes the engagement of another in driving relationship relative to the needle bar frame.

A further object is to provide in the aforementioned device, a cam changing means, which is simple, trouble-free, efficient, and inexpensive to produce.

Other objects will become readily apparent from the following detailed description of two preferred embodiments of the invention, which are given by way of illustration only and which are not intended to be limitative of the possible variations and applications of the inventive concept, which description is referred to the appended drawings, in which:

FIGURE 1 is a partially cut-away front elevation view of a sewing machine which incorporates the device of this invention;

FIGURE 2 is a back elevation view (relative to FIG- URE 1) of only the ornamental pattern sewing device of this invention;

FIGURE 3 is a left-side elevation view (relative to FIGURE 2);

FIGURE 4 is a section view taken along line IV-IV of FIGURE 2;

FIGURE 5 is an enlarged partial sectional view of the stack of pattern cams in accordance with a first embodiment of this invention;

Patented Dec. 5, 1967 FIGURE 6 shows a portion of FIGURE 5 on an enlarged scale; and,

FIGURE 7 is an enlarged partial sectional view, corresponding to FIGURE 5, in accordance with a second embodiment of this invention.

With reference to FIGURE 1, this shows the overall relationship of a pattern sewing device to the needle bar in a sewing machine. It is seen that the machine comprises a hollow housing H which supports rotatable main shaft 1 which in turn is driven 'by being connected to a conventional driving means (not shown). Main shaft 1 is connected through appropriate connection means 2 to a needle bar 3 which is mounted for reciprocating movement in needle bar support 4. Rotary motion of shaft 1 is transmitted into reciprocating motion of bar 3 through connection means 2.

The longitudinal line of sewing, that is, the direction in which the fabric moves, is along a line which is perpendicular to the plane of FIGURE 1. If the needle bar 3 were to reciprocate in a single plane the sewing line would be essentially a straight line. On the other hand, in the machine shown in FIGURE 1, the needle bar 3 can oscillate in a horizontal direction, i.e., from right to left or generally parallel to the axis of main shaft 1 so that the sewing line which results from this oscillatory movement will correspondingly define a back and forth continuous line rather than a straight line. This is possible by virtue of the fact that support 4 is not rigidly mounted to housing H but is instead resiliently mounted thereto by means of flat leaf spring 5. The opposite ends of spring 5 are secured to housing H and to support 4 by means of screws 6 and 7, and there is a space between housing H and the top of support 4 so as to permit freedom of movement of support 4.

At the right hand side of the machine, mounted within housing H, is a pattern sewing device generally designated by 8. The device is drivingly associated with transversely reciprocable rod 10, one end of which abuts against one side of support 4. Device 8 reciprocates rod 10 in accordance with a certain pattern of oscillatory movement, and rod 10 in turn imparts this oscillatory movement to support 4.

The normal, relaxed disposition of leaf spring 5 is such that with rod 10 at its extreme right hand position, the frame 4 will abut the left end of rod 10. In other words, spring 5 of itself returns the support 4 and bar 3 to the extreme right position while rod 10 serves to push support 4 to its extreme left position.

With general reference to FIGURE 1 and with specific reference to FIGURES 2 and 3, it is seen that the pattern sewing device 8 comprises a plurality of working elements supportingly mounted on a vertical base plate 11 which in turn is secured to housing H by means of machine screws 9. At the upper and lower end portions of plate 11 are mounted bearing supports 12 which rotatably support cam shaft 13. Shaft 13 is drivingly connected to the machine main shaft 1 by means of the helical gear 14 and the worm 15, each respectively keyed onto the shafts 13 and 1. An axially movable cam housing member 16 is mounted about cam shaft 13 for axial movement relative thereto, for example, in the direction of arrow Y (FIGURE 3) or oppositely thereto. Extending rigidly from one side of the housing member 16 is a vertical rack gear 20 which meshes with a gear Wheel 21 which in turn is rigidly keyed to hub 22. A hand control knob or wheel 23 is also rigidly connected to hub 22, with elements 21, 22 and 23 all being rigidly rotatable together about pivot pin 24 which is supported on base plate 11. It is, therefore, seen that rotation of the hand wheel 23 will rotate wheel 21 and in turn will vertically move the housing 16.

A stack comprising a plurality of separate cams is generally designated by 17. These cams are mounted on cam shaft 13 so as to be rotatable therewith but axially slidable therealong by means of a key 19 and keyway 18 arrangement. For example, the keyway 18 extends along the shaft 3 while the key 19 is rigidly a part of the cams. The cams are rotatable with shaft 13 within and relative to the housing member 16; however, the cams are axially fixed relative to the member 16 so that the housing 16 moves the cams axially along shaft 13 as the housing is moved through manipulation of hand wheel 23.

The cams are stacked within housing 16 as is shown in FIGURES 5 and 6. Numerals 36, 37 and 38 designate three separate cams each having a distinct outer circumferential cam profile 39, 40, 41, respectively, each profile corresponding to a different sewing pattern. Between adjacent cams there are respective pairs of distancing collars or spacers 42, 43 and 43, 44 which maintain a suitable spacing between the respective cams so as to permit the cam follower lever 30 to contact only one cam at a time.

The cams are drivingly associated with the rod by means of a lever 34 which is pivotably mounted at 35 on the base plate 11. The top end of lever 34 is connected to one end of rod 10 by any suitable means, while the bottom end of lever 34 is abuttingly engaged by one end 33 of cam follower lever 30. As will be seen from FIG- URE 4, the other end 32 of cam follower lever 30 rides against a respective cam profile. The follower lever 30 is pivotably mounted at 31 to base plate 11 so that as the cam rotates, its profile causes follower lever 30 to oscillate about pivot 31 in conformity to the ups and downs in the cam profile, and this oscillatory movement of lever 30 is transmitted to lever 34 which in turn transmits it to rod 10.

It will here be noted that since the leaf spring 5 normally biases rod 10 in direction X (FIGURE 2), this in turn biases lever 34 in the counter-clockwise direction in FIGURE 2 with its bottom end 50 pressing against end 33 of follower lever 30 whereby end 32 of lever 30 (see FIGURE 4) is biased into contacting relation with the respective cam profile. In order to accurately position each respective cam in driving relationship with end 32 of follower lever 30, an arcuate disc 25 having peripheral notches 26, equal in number to the number of cams, is rigidly mounted on hub 22 to be rotatable therewith. A second leaf spring 28 is mounted at one end thereof to the base plate 11 by means of screw 29, while a free end portion 27 of said spring is convexly shaped to correspond to the contour of the notches 26 and to slide from one notch to another, said free end portion being biased into said notches. Each notch 26 corresponds to a different cam being engaged by follower lever 30, so that with the spring end 27 engaging any one notch 26, the housing 16 and cam 17 assembly is locked in proper operating position for a particular cam. Another cam can be substituted by simply turning hand wheel 23 until the spring end 27 slides into another of the notches. A suitable indicator means can be provided on the outside of housing H and on hand wheel 23 to indicate the positions of the hand wheel which correspond to the respective cams being in driving position.

An important feature of the present invention resides in the particular shape of the follower end 32 of the follower lever 30. This shape permits a shifting from one cam of smaller diameter to a cam of larger diameter without necessitating a prior lateral shifting of the follower lever to a position out of the way of the larger cam.

With reference to FIGURES 5 and 6, which show a first preferred embodiment of this feature, it is seen that the follower end portion 32 of lever 30 includes upper and lower inclined surfaces or bevelled edges 46 and 45, respectively. An important consideration is that the radial length A of these surfaces slightly exceeds the radial difference in height B between the lowest radial surface 49 of the smaller cam 37 and the highest radial surface 48 of the larger cam 33, so that when the cams are shifted upwardly (arrow Y in FIGURE 5) the corner 47 of larger cam 38 will abut the inclined surface 45 and will thereby gradually and smoothly push lever 30 radially outward (to the left in FIGURES 5 and 6) as the cam 38 moves upwardly to assume the position which cam 37 presently is shown to occupy in FIGURE 6. It is to be understood that for practical reasons dimension A should slightly exceed dimension B; however, theoretically, dimension A should be at least equal to dimension B.

Conversely, when the cams are shifted downwardly from their position as shown in FIGURE 5, the surface 46 on lever 30 acts upon corner 50 of cam 36 analogously to the action of surface 45 on corner 47.

'It should furthermore be noted that when the shifting occurs from a larger cam such as 38 to a smaller cam such as 37, the follower lever 30 is not suddenly released by the larger cam 38 to thereby abruptly strike against the smaller cam 37. Instead, the corner 47 gradually moves downwardly along inclined surface 45, as cam 38 is shifted downwardly, so that lever 30 is smoothly and gradually eased against the cam 37.

With regard to the embodiment of FIGURES 5 and 6, it should be noted that the axial spacing between cams, as provided by spacers 43 and 44, is slightly greater than the axial width W of the bevelled edges 45, 46. This is necessary in order to prevent any part of edges 45, 46 from contacting the corners 47 or 50 on the adjacent cams while the cams are in the position shown in FIG- URES 5 and 6.

It will also be noted from FIGURES 5 and 6 that the surfaces 45 and 46 are bevelled in the plane which includes the rotational axis of the cams 36, 37, and 38. In other words, the surfaces 45 and 46 are bevelled in an axial direction, that is a direction parallel to the direction in which occurs the axial shifting of the cams.

FIGURE 7 shows a second preferred embodiment of the inventive concept of this application. According to this embodiment, instead of the follower lever end portion having inclined surfaces, it has horizontal or straight surfaces and the cams themselves are provided with bevelled edges. In FIGURE 7, the respective cams are designated 51, 52 and 53. Cam 52 is shown to be the smallest of the cams and is located between larger cams 51 and 53 which each include bevelled edges 54 and 55. It is to be noted that the axial height of edges 54, 55 (which is analogous to dimension A in FIGURE 6) should exceed or be at least equal to the maximum height difference (which is analogous to dimension B in FIG- URE 6) between adjacent cams.

With reference to this second embodiment, it is noted that the three cams are axially juxtaposed, that is, axially contacting each other and that the axial width of the end of lever 30 which rides against the profiled cam surfaces must be narrower than the axial width of any cam in order to avoid possibility that the end of lever 30 rides over two adjacent cam profiles at a time.

What is claimed is:

1. A sewing machine for sewing an ornamental pattern and the like, comprising: a needle bar means including an axially reciprocable needle bar, said needle bar means being transversely displaceable relative to a straight sewing line to cause said needle to sew on opposite sides of a straight sewing line, a pattern sewing device for transversely displacing said needle bar means, said device comprising a plurality of separate cams, said cams being coaxially mounted adjacent to each other on a rotatable cam shaft and each one having an outer circumferential profiled surface, each said surface comprising portions of varying radial dimension relative to said surface on an adjacent cam, said cams being rotatably fixed on said cam shaft but being axially displaceable along said cam shaft to alternately place each of said cams in a driving position, a shift means to axially displace said cams along said cam shaft, a cam follower lever pivotally mounted and including a cam follower portion having a sliding surface, said cam follower portion being resiliently biased with said sliding surface bearing against the outer profiled surface of whichever cam is in said cam driving position, said shift means comprising radially acting means which act against said cam follower lever in response to axial movement of said cams to automatically and uniformly pivot said lever cam follower portion radially with respect to the profiled surface of the cam which is in said driving position and onto the surface of a next adjacent cam profiled surface upon said cams being axially displaced in either direction along said cam shaft, and means to drive said cam shaft.

2. The machine of claim 1, said radially acting means comprising a bevelled edge adjacent to said sliding surface on said cam follower portion, said edge being bevelled in an axial direction of said cams and having a radial dimension at least equal to the maximum radial height difference between the profiled surfaces of any two adjacent cams.

3. The machine of claim 1, said radially acting means comprising a bevelled edge adjacent to said profiled cam surfaces on those of said cams having a larger radial extent than next adjacent ones of said cams, said bevelled edge having a radial extent at least equal to the maximum radial height difference between the profiled surface of the cam having the bevelled edge and the profiled surface of the next adjacent cam.

4. The machine of claim 2, wherein said profiled cam surfaces are axially spaced apart from each other a distance in excess of the axial distance of each said bevelled edges.

5. The machine of claim 3, wherein said cams are in axially contacting relationship with each other and wherein the axial width of said cam follower portion is less than the axial width of any one cam.

References Cited UNITED STATES PATENTS 3,000,333 9/1961 Moro 1l2l58 3,034,462 5/1962 Hida 112158 3,177,835 4/1965 Tanaka l12*158 PATRICK D. LAWSON, Primary Examiner. 

1. A SEWING MACHINE FOR SEWING AN ORNAMENTAL PATTERN AND THE LIKE, COMPRISING: A NEEDLE BAR MEANS INCLUDING AN AXIALLY RECIPROCABLE NEEDLE BAR, SAID NEEDLE BAR MEANS BEING TRANSVERSELY DISPLACEABLE RELATIVE TO A STRAIGHT SEWING LINE TO CAUSE SAID NEEDLE TO SEW ON OPPOSITE SIDES OF A STRAIGHT SEWING LINE, A PATTERN SEWING DEVICE FOR TRANSVERSELY DISPLACING SAID NEEDLE BAR MEANS, SAID DEVICE COMPRISING A PLURALITY OF SEPARATE CAMS, SAID CAMS BEING COAXIALLY MOUNTED ADJACENT TO EACH OTHER ON A ROTATABLE CAM SHAFT AND EACH ONE HAVING AN OUTER CIRCUMFERENTIAL PROFILED SURFACE, EACH SAID SURFACE COMPRISING PORTIONS OF VARYING RADIAL DIMENSION RELATIVE TO SAID SURFACE ON AN ADJACENT CAM, SAID CAMS BEING ROTATABLY FIXED ON SAID CAM SHAFT BUT BEING AXIALLY DISPLACEABLE ALONG SAID CAM SHAFT TO ALTERNATELY PLACE EACH OF SAID CAMS IN A DRIVING POSITION, A SHIFT MEANS TO AXIALLY DISPLACE SAID CAMS ALONG SAID CAM SHAFT, A CAM FOLLOWER LEVER PIVOTALLY MOUNTED AND INCLUDING A CAM FOLLOWER PORTION HAVING A SLIDING SURFACE, SAID CAM FOLLOWER PORTION BEING RESILIENTLY BIASED WITH SAID SLIDING SURFACE BEARING AGAINST THE OUTER PROFILED SURFACE OF WHICHEVER CAM IS IN SAID CAM DRIVING POSITION, SAID SHIFT MEANS COMPRISING RADIALLY ACTING MEANS WHICH ACT AGAINST SAID CAM FOLLOWER LEVER IN RESPONSE TO AXIAL MOVEMENT OF SAID CAMS TO AUTOMATICALLY AND UNIFORMLY PIVOT SAID LEVER CAM FOLLOWER PORTION RADIALLY WITH RESPECT TO THE PROFILED SURFACE OF THE CAM WHICH IS IN SAID DRIVING POSITION AND ONTO THE SURFACE OF A NEXT ADJACENT CAM PROFILED SURFACE UPON SAID CAMS BEING AXIALLY DISPLACED IN EITHER DIRECTION ALONG SAID CAM SHAFT, AND MEANS TO DRIVE SAID CAM SHAFT. 